Making of alkali cyanogen compounds.



UNITED s'rawnur OFFICE.

JOHN COLLINS CLANCY, OFiCOLORADO SPRINGS, COLORADO, A SSIGNOR OF FIFTY-ONE ON-E-HUNDREDTHS TO PORTLAND GOLD MINING COMPANY, OF COLORADO SPRINGS, COLORADO, A CORPORATION OF WYOMING.

MAKING or ALKALI cYANoGnN coiiirzeouuns.

No Drawing.

To all whom it may concern Be it known that I,J0HN COLLINS CLANCY, a subject of the King of Great Britain, having declared my intention of becoming a citizen of the United States, at present residing at Colorado Springs, in the county of 'El Paso and State of Colorado, have invented certain new and useful Improvements in the Making fication.

My invention relates to novel methods of.

mercial cyanamid, the fusing of this com pound is rendered difiicul't unless a very large proportion of flux is used. The salt which gives the largest yield of cyanid when heated with cyanamid in presence of carbon-is, potassium carbonate. The use of potassium carbonate in this way for the commercial production of potassium cyanid from cyanamid'is absolutelyprohibitive on account of its present cost. Inventors have discovered that in this, like in all other But, nowhere has the peculiar action been observed which is produced when an alkaline sulfid, such, for example, sodium sulfid is used in combination with a halogen salt, 11. 6. sodium chlorid. The time required for the formation of cyanid by this means specification of Letters latent.

Application filed June 22, 1912. Serial No. 705,173.

of Alkali Cyanogen Com-, pounds, of which the following is a speci- Patented Oct. 6, 1914.

is reduced to a few minutes, and in no case is actual fusing or melting required and it is a remarkable'fact that only a'small quantlty of the alkline ,sulfid is sufiicient to produce the desired successful result. At

first, it might be supposed that the use of sodium sulfid used in this manner will bring about "the formation of sulfocyanid. This con ecture is correct, as the formation of sul ocyanlds depends upon the temperature, the proportion and kind of carbon used. However, if a mixture of cyanamid and sodium sulfid together with pulverized coal be heated quickly to a temperature of say somewhere between 800 to 1000", C.-no formation of sulfocyanids takes place, and the conversion of cyanamid into cyanid is practically complete.

I have found that if equal weights of sodium sulfid and cyanamid are heated with a proportion of carbon equal to one-fifth weight of the cyanamid taken to a temperature of from about 800 to 1000 C.-alkalin e cyanid was formed to the extent of 25% of the Weight of the cyanamid taken. The resulting product was contaminated with a large amount of soluble sulfids. On considerably increasing the proportion of carbon the. yield of cyanid was not increased. On the other hand if equal weights of cyanamid and sodium sulfid were heated to the same temperature with the same proportion of carbon in the form of softcoal (hydrocarbon) the yield of cyanid was increased to 55% of the weight of cyanamid taken this product Wasalso contaminated with a large amount of soluble sulfids. These soluble sulfids would mitigate against its use as a solvent for gold and would require extra treatment to eliminate soluble sulfids. After numerous experiments I discovered that it was possible to obtain a product free from soluble sulfids containing a high percentage of cyanid, and at once readily applicable in a commercial way for use in the treatment of gold and silver ores. This result was accomplished by heating cyanamid with an equal weight of a mixture consisting of 50% sodium sulfid and 50% sodium chlorid with the addition of pulverized coal in proportion to one-fifth the weight of cyanamid taken.

The nature of the action between sodium easily explained by assuming the following equation:

The nature of the action between the sodium sulfid in conjunction with the sodium chlor d and nascent carbon upon the cyanamid 1s diflicult to explain; it may be that a passing combination takes place between the sodiums of the sodium chlorid and the sodium sulfid in presence of nascent carbon resulting in the formation of an insoluble salt, CaCl ,CaS after the equation:

Practical experiments have produced the following results: 1. 10 grams of calcium cyanamid mixed with 5 grams sodium sulfid, 5 grams sodium chlorid and 2 grams of pulverized coal heated to a temperature of from about 800 to 1000 C, with the exclusion of air gave a yield of cyanid equivalent to of the weight of cyanamid taken. This mixture when dissolved in water gave no test for'solublesulfids, the solution being very active on gold leaf. On the other hand 10 grams of, calcium cyanamid mixed with 10 grams of sodium sulfid and 2 grams of pulverized coal heated to a temperature of from about 800 to 1000 C. with exclusion of air gave a yield of cyanid equivalent to 55% of the weight of cyanamid taken. This mixture when dissolved in water gave a very large amountof soluble sulfids and this solutionshowed no action upon gold leaf even after standing ten days. Although cyanid was present no action upon thegold leaf would take place until allthe sulfids were oxidized. This product would in all probability be useless as a gold solvent unless the sulfids were oxidized before or during treatment of the ore. cyanid is not used for the purpose of ore treatment this means of producing cyanid from cyanamid might have its use.

In carrying my process into practice the finely ground cyanamid is thoroughly mixed with the finely divided sodium sulfid and sodium chlorid together with pulverized coal and'heated in a crucible or a furnace container.

Of course in cases where with exclusion of air to a temperature of from about 800 to 1000 0. As soon as the volatile products cease'to be given 01f, which inv practice generally takes about fifteen or twenty minutes after the mixture has been brought to a good red heat; the crucible or container is removed from the source of heat or the source of heat removed from the The mixture is then allowed to cool with exclusion of air. The contents of the container now contains cyanid in the form of-sodium cyanid mixed of course with insoluble compounds already described.

Having now described my invention and examples of different ways of carrying into effect, it will be understood that various modifications and changes in the described processes may be made and equivalent substances maybe employed without departing from the spirit of my invention and without exceeding the scope of my claim.

The term carbonaceous material as em ployed in the claims is used to denote the hydrocarbons or other carbon-containing material capable of yielding carbon in the process of treatment described, such as hard and soft coal.

What I claim and desire to procure by Letters Patent is:

l. The process of producing cyanogen compounds which consists in heating calcium cyanamid with alkali-metal-sulfid in presence of a carbonaceous material at reacting temperatures.

2. The process of producing cyanogen compounds which consists in heating calcium cyanamid with its own weight of a mixture composed of equal weights of sodium sulfid and an alkali-metal salt in presence of carbonaceous material at reacting temperatures.

3. The process of producing cyanogen compounds which consists in heating calcium cyanamid with its own weight of a mixture composed of equal weights of sodium sulfid and sodium chlorid in presence of carbonaceous material at reacting temperatures.

JOHN COLLINS CLANCY.

Witnesses: W. A. HILLER, E. F. DRAPER. 

